Complicated case -- help with CPAP pressure and other

Hi everyone,

I'm fairly new to this board, but know you all are really helpful when it comes to figuring out problems with CPAP and treatment.

I've been using CPAP for over three years and CPAP was retitrated at 7.5 mm pressure about 2 years ago. During that sleep study, anything above 8.5 pressure would increase my arousals a lot. I guess the assumption is that higher pressures induce unstable ventilatory response and that I have a low arousal threshold.

So I stuck with 7.5 or 8mm pressure but had a sleep endoscopy to see where the airway restriction was occurring. Results indicated that I'd respond to a MAD. I can't use the MAD at full therapeutic levels since it changes my bite / jaw a lot. So I've been using the MAD at an intermediate setting together with CPAP, and I've felt a bit better since doing that.

Still not great though.

The more I research, the more I think I'm a complicated case. First off, I have UARS (upper airway resistance syndrome) not OAS and suffer from RERAs (i.e arousals) at night more than apnea. Indicating I have a low arousal threshold.

I've been using a pulse oximeter for past six months and my SP02 hardly falls below 93-92% ever. Indication is that I may also have a high chemoreflex response (i.e. the sympathetic response we get to increases in blood CO2 levels / drop in 02). This means that even smaller drops in SPO2 result in arousals for me.

I'm attaching here a picture of a typical night with CPAP including heart rate. What I did in sleepyhead was enable flow limitations at 20 and 50% which adds flag events that otherwise wouldn't be there. Since I'm assuming I am more sensitive to any blood oxygen/CO2 changes etc at night, I think these more subtle flow limitations capture my problem better.

My questions are:

Has anyone seen a similar case before ? If so, what did they do ?

Why do higher cpap pressures increase my arousals at night ? Why do they induce unstable breathing patterns ? Would a Bipap or a ASV enabled machine be an option for me ?

Thanks so much for any and all ideas / advice on this!

You have an Auto CPAP, but you're using it as a fixed machine. Perhaps you might want to turn the max up somewhat, especially given that you're not having any clear airway events.

D.H. I believe the issue is that when the pressure exceeds 8 there are more arousals.

dcg494 This is just an observation..

Your heart rate is a little low and your respiration rate is a little high. Both of these are controlled by your nervous system and I don't know if this is significant or not.

Do you sleep on your back? Have you tried not doing it and seeing what your 'snore score' is like then?

Thanks for the responses!

@HoseCrusher

How can you tell HR is a bit low and respiration is high ? At this point I do have a sense my nervous system is a big part of the problem. Do you know how a high respiration rate affects you ? (e.g. induce hypocapnia and lead to hyperventilation, or.. ?) And what can be done about that ?

I was actually thinking of setting off the EPR. I'm at a loss to figure out the persistent tiredness, but have a feeling the EPR destabilizes my breathing pattern.

@Julie

I think I sleep on my back sometimes at night, I catch myself waking up in the morning at times on my back, and events tend to cluster at night. How can I prevent sleeping on my back though ? Tennis ball i guess ?

Attaching here another photo, because I know my therapy LOOKs like it's good, but it's definitely not. I feel horrible most days, extremely tired. Pushed up the sensitivity on the UF#2 to 60% -- I am sure that w every gray flag I have a microarousal.

My last sleep study found 40+ arousals per hour, but they were happy when they lowered the AHI and RERAs a bit (still with a lot of arousals) and sent me home. Anything above 8cm pressure ruins me and I'm at a complete loss. Tried MAD, etc.

Is there nothing else that can be done ?

A backpack with towels inside could help... tennis ball only works for some. You can also buy foam wedges to put behind you, but they can slide around unless backed up by a wall.

dcg494 wrote: ↑

Sun Jul 22, 2018 2:51 am

Is there nothing else that can be done ?

Why are you in cpap mode on an apap?

Since you're already sleeping like crap, why don't you try something different.

auto mode, min 8, max 10, ... see what happens, if no difference, then go for 8.5 or 9 min.

It's entirely possible your earlier evaluations were in error.

dcg494, I am just coming from a general perspective. Athletes in top condition usually have a heart rate in the low 50's and may even dip a little lower than that. Normal people usually end up in the 60's. You are a little lower than that and I didn't get the impression that you were in top athletic condition. Please correct me if I am wrong.

Resperation rate is more variable. Usually people end up in the 10 - 14 rate but that also is very general.

Is this normal for you? I don't know.

Is this a sign that something is starting to be amiss? Once again I don't know.

I am just looking at your data and noticing something a little bit different. Your doctor may be able to shed some light on this, or you can search your heart out and see if it is worth consideration.

My philosophy is that when grasping at straws let's take the time to examine each straw and gain the most information we can.

HoseCrusher wrote: ↑

Sun Jul 22, 2018 1:47 pm

My philosophy is that when grasping at straws let's take the time to examine each straw and gain the most information we can.

TOTALLY agree with that, great approach Hosecrusher so thanks for the feedback. My heart is actually ok, I do go running and to the gym, it helps with the sleep! My Heart rate has always been pretty low.

palerider wrote: ↑

Sun Jul 22, 2018 11:56 am

Why are you in cpap mode on an apap? auto mode, min 8, max 10, ... see what happens, if no difference, then go for 8.5 or 9 min.

It's entirely possible your earlier evaluations were in error.

Thanks Palerider, I have it in apap so I can use a-flex and also get measurements on flow rate (respironics only does that on apap mode).

The problem with apap is that my UARS is so subtle that the machine doesn't detect it. When I had it on apap, the machine would hardly ever respond.

In the sleep lab those arousals (RERAs) went down from ~40/hr to ~15/hr with pressure at 8cmH20 and then shot back up to 46cmH20 at 9cm. My experience experimenting w higher pressure corroborates that -- I wake up a lot with a beating heart and feel horrible next day.

If I could figure out what's causing the issue with higher pressure, I could perhaps solve it and raise my pressure to fix the residual RERAs. Any ideas on what could be explaining the higher pressure issue ?

Go back to apap mode but set the minimum to equal the maximum to mimic cpap mode...then you won't lose the Flow limitation flagging or whatever you like about APAP but you still get the fixed pressure of cpap mode if that is what you want to use.
APAP mode doesn't have to have a range of pressures to roam around in.

With the machine in auto/apap mode and the minimum and maximum settings the same...the pressure won't move if that is what you want and you don't lose any of the flags that aren't available in cpap mode.
So same functionality but not lose anything.

It's showing cpap mode right now...not auto/apap mode.

Pugsy wrote: ↑

Mon Jul 23, 2018 5:13 am

Go back to apap mode but set the minimum to equal the maximum to mimic cpap mode...then you won't lose the Flow limitation flagging or whatever you like about APAP but you still get the fixed pressure of cpap mode if that is what you want to use.

Yep, thanks Pugsy, this is what I've been doing for a while now. Helps flag events, though my UARS is so subtle, I also have to use the user-defined flags in sleep head to see the other ~80 flow limits or so I get per night.

Based on my research so far, I think I need a new CPAP -- I need to go to a Resmed which allows for EPR, or a bipap. Here's a good article on it : http://www.apneaboard.com/wiki/index.ph ... _and_BiPAP

I am thinking either the Airsense 10 for her or the Aircurve Vauto. My pressure requirements are pretty low -- probably 9-10, though I never could reach those pressures on the respironics (couldn't tolerate it, and c-flex doesn't allow enough PS for me).

So I'm thinking Airsense 10 could be enough. But does anyone have any recommendations ? Is it worth paying the extra to have the option of another 1-2 cm of PS should I need it ? Do you think I would need it ?

I like PS of 4 with the bilevel machines but I can get by with the PS/EPR of 3 with the AirSense machine.
With the Respironics and Flex the most PS you can get is 2 and even then only if your breathing is forceful.
For this reason I prefer ResMed way of doing the exhale relief.

For me the slight difference between using EPR at 3 and the bilevel with 4 PS wasn't a problem but I will admit that I liked better. I would love to have the AirCurve 10 VAuto...just haven't found a screaming hot deal on one like I did the AirSense 10 AutoSet for Her.

dcg494 wrote: ↑

Mon Jul 23, 2018 1:48 am

Thanks Palerider, I have it in apap so I can use a-flex and also get measurements on flow rate (respironics only does that on apap mode).

According to the screenshot, you *DON'T* have it in apap mode.

dcg494 wrote: ↑

Mon Jul 23, 2018 1:48 am

The problem with apap is that my UARS is so subtle that the machine doesn't detect it. When I had it on apap, the machine would hardly ever respond.

You've got it on fixed pressure, it's not going to do anything for you. 'hardly ever' respond is better than 'does nothing'... though maybe not by a lot.

That's right Palerider, that was an older screenshot where it was set at cpap. And good point, a little is better than nothing, but the flow limitation detection on the system one isn't sensitive enough. The FL flags in sleepyhead are only 1/10 of what shows up with sleepyhead's user-defined FL flags. My UARS is really subtle, and -- like the sleep labs/science to date, seems the machines have to still catch up with UARS to adequately treat.

So, in short, I prefer to not have pressure changes at night until a) I can have more pressure support to tolerate higher pressures, and b) until I find a better, more sensitive and fine-tuned system that does the trick. Which @pugsy

Pugsy wrote: ↑

Mon Jul 23, 2018 10:17 am

I would love to have the AirCurve 10 VAuto...just haven't found a screaming hot deal on one like I did the AirSense 10 AutoSet for Her.

How have you found the autoset algorithm on the ;airsense for her' ? Seems you've tried a respironics system before, are you able to compare ? And generally, do you know if the Aircurve VAuto can respond to FLs the same way as the airsense ?

Lot's of questions, but thanks a lot for any help on the above!

dcg494 wrote: ↑

Mon Jul 23, 2018 12:25 pm

That's right Palerider, that was an older screenshot where it was set at cpap. And good point, a little is better than nothing, but the flow limitation detection on the system one isn't sensitive enough. The FL flags in sleepyhead are only 1/10 of what shows up with sleepyhead's user-defined FL flags.

There's no such thing as a user defined FL flag on sleepyhead.

All you can define on sh are volume reductions. Flow limitations are a different thing.

Think of FL as breathing through a small straw, you can still take a full volume lung filling breath, so there's no hypopnea (reduced volume) but you have to work harder to take that breath.

All you can program in sh are volume reduction flags... Ie, smaller or shorter hypopneas.